This disclosure relates to analyzing information gathered using multiple analytical techniques.
Analysis of chemical samples can yield a wide variety of information regarding the samples. The information can include, e.g., the identity of constituent components, the quantities of constituent components, time information such as the rate of change of the composition of the chemical sample, position information such as the physical disposition of constituent components within the sample, and detailed chemical information, such as the stability of the constituent components and the nature of interactions between constituent components.
Although chemical samples can yield such a wide variety of information, the actual information gathered by any one analytical technique is often quite limited. For example, a pH meter gathers information regarding the concentration of hydrogen ions in a chemical sample (i.e., how “acidic” a sample is). As another example, mass spectrometry gathers information regarding the mass-to-charge ratio of charged species generated from a sample. As yet another example, chromatography gathers information regarding interactions between the constituent components of a sample and a stationary phase.
The information gathered by multiple analytical techniques can be combined to improve the characterization of a chemical sample. FIG. 1 is an example of a combination of information gathered by multiple analytical techniques, namely, a graph 100. Graph 100 includes an axis 105, an axis 110, and a number of peaks 115, 120, 125, 130. Position along axis 105 embodies the mass-to-charge ratio of charged species generated from the sample, as determined by mass spectrometry. Position along axis 110 embodies the strength of the interactions between the constituent components of the sample and a stationary phase, as determined by gas chromatography. The strength of the interactions between the constituent components is denoted as a “scan number” that indicates the number of a mass spectrometry scan in a series of such scans that were made on the effluent of a chromatograph. Peaks 115, 120, 125, 130 each represent different constituent components of the sample.
The combination of mass-to-charge ratio information and interaction strength information in graph 100 can improve the characterization of the sample. For example, peaks 115, 120 overlap at position P1 along axis 105. This overlap indicates that the charged species generated from the constituent components represented by peaks 115, 120 have the same mass-to-charge ratio. If only mass-to-charge ratio information were available, peaks 115, 120 (and the constituent components that they represent) would be indistinguishable. However, the interaction strength information provided by gas chromatography allows peaks 115, 120 and the constituent components that they represent to be distinguished.
As another example, peaks 125, 130 overlap at position P2 along axis 110. This overlap indicates that the constituent components represented by peaks 125, 130 have the same strength of the interaction with a stationary phase. If only strength of the interaction information were available, peaks 125, 130 (and the constituent components that they represent) would be indistinguishable. However, the mass-to-charge information provided by mass spectrometry allows peaks 125, 130 and the constituent components that they represent to be distinguished.